Co_2(CO)_8红外光谱及羰基钴氢催化活性的理论研究  

Theoretical Studies on the IR Spectra of Co_2(CO)_8 and the CatalyticActivities of HCo(CO)_3 and HCo(CO)_4

作　　者：侯若冰[1] 义祥辉[2] 陆丹梅[3] 

机构地区：[1]广西师范大学化学系,桂林541004 [2]广西师范大学资源与环境学系,桂林541004 [3]广西广播电视大学理工部,南宁530022

出　　处：《北京大学学报（自然科学版）》2002年第6期750-755,共6页Acta Scientiarum Naturalium Universitatis Pekinensis

基　　金：国家自然科学基金 ( 2 986 30 0 1);广西高校科研基金;广西师范大学博士启动基金资助项目

摘　　要：在B3LYP 6 31G 水平上对Co2 (CO) 8红外光谱及烯烃氢甲酰化催化反应的催化活性中间体HCo(CO) 4和HCo(CO) 3 的结构进行了优化及相关计算 ,结果表明 :( 1)Co2 (CO) 8的两种稳定构象态分别具有C2v和D3d对称性 ,计算所得的结构数据与实验值具有极好的一致性。C2v对称性的Co2 (CO) 8比D3d对称性的Co2 (CO) 8的能量低 2 8 80kJ mol;( 2 )C2v对称性的Co2 (CO) 8的红外吸收峰的计算结果与实验值极为接近 ;( 3)催化反应的活性中间体HCo(CO) 4和HCo(CO) 3 的稳定构象态分别具有C3v和C2v对称性 ,其中HCo(CO) 3 比HCo(CO) 4具有更高的催化活性 ;( 4 )催化反应中乙烯与HCo(CO) 3 形成了相对稳定的π配合物 ,该配合物中π配键的键能约为 10 0 80kJ mol。Studies on the band positions in IR spectra of Co-2(CO)-8 with the C 2v symmetry and the catalytic activities of the species,HCo(CO)-3 and HCo(CO)-4,in the reaction of the olefin hydroformylation have been carried out by using quantum chemical calculation at the B3LYP/6-31G* level.Two structures of the Co-2(CO)-8,the geometry of C 2v symmetry,as well as the conformation of D 3d symmetry,have been optimized and the structure optimized of C 2v symmetry Co-2(CO)-8 agrees well with experimental structure and is 28 80*!kJ/mol more stable than D 3d one.The band positions in IR spectra of C 2v symmetry Co-2(CO)-8 is well in accord with the experimental studies.It is found that the active catalytic species,HCo(CO)-3 and HCo(CO)-4,have C 2v and C 3v symmetries,respectively,and that the catalytic activity of HCo(CO)-3 is better than HCo(CO) 4.In addition,the π bond between ethene and HCo(CO)-3 has been formed in the coordinate catalytic reaction and the theoretical bond energy is 100 80*!kJ/mol.

关 键 词：八羰基合二钻 三碳基一氢合钴 四碳基一氢合钴 电子结构 红外光谱 催化活性 烯烃 氢甲酰化 催化反应 

分 类 号：O643.3[理学—物理化学]